Summary Preliminary experience using a balloon assisted technique (BAT) for embolization of arteriovenous malformations (AVM) is reported. Two patients with large pericallosal AVMs were successfully embolized with Onyx under Scepter C balloon catheter flow arrest.

Clinical presentation One patient presented with a large intraventricular hemorrhage and hydrocephalus. The second patient presented with a long history of seizures and a small intracerebral hemorrhage. Both patients demonstrated extensive interhemispheric AVMs with multiple arterial feeders, predominantly from the pericallosal arteries.

Intervention A Marathon microcatheter was navigated into the target arterial feeders and a Scepter C occlusion balloon catheter was inflated immediately proximal. Under flow arrest, Onyx was injected via the microcatheter with excellent nidal penetration. In both cases, there was complete angiographic obliteration of the treated component of the AVM.

Conclusions Onyx embolization under balloon catheter flow arrest allows for greater nidal penetration of embolic material and improved reflux control. The technique is limited by the current deliverability of balloon catheters and the potential risk for earlier embolization of dangerous anastomosis.